OM System's compact PRO telephoto zoom — 80-300mm equiv at constant f/4 with weather sealing and lightweight design.
The OM System M.Zuiko Digital ED 40-150mm f/4 PRO was released in 2022 as a compact telephoto zoom for Micro Four Thirds, covering 80-300mm equivalent at constant f/4 with IP53 weather sealing and freeze protection to -10°C. Fifteen elements in 9 groups. Seven rounded aperture blades. 62mm filter thread. At 382g. 0.70m MFD (0.21x maximum magnification). No in-lens IS.
The optical design uses 15 elements in 9 groups (2 ED + 1 Super ED + 1 HR + 2 aspherical elements). Seven rounded aperture blades. The 62mm filter thread. At 382g the lens is compact for a constant f/4 telephoto. Minimum focus distance of 0.70m (0.21x maximum magnification). No optical IS — relies on in-body IBIS. IP53 weather sealed, freeze-proof to -10°C. f/4 constant aperture. MFT image circle (80-300mm equivalent).
The 382g weight positions the 40-150mm f/4 PRO as the compact telephoto zoom complement to the heavier 40-150mm f/2.8 PRO (760g): at just over half the weight, the f/4 version delivers the same IP53 weather sealing and optical quality in a notably smaller package. The tradeoff is one stop of aperture — at f/4, the lens requires more light or higher ISO for equivalent exposure to the f/2.8 version.
On the used market the OM System 40-150mm f/4 PRO is available at mid-range MFT telephoto pricing. Condition checks: AF response, weather sealing, 62mm front element for marks, zoom ring smoothness. No in-lens IS. Compatible with all Micro Four Thirds bodies from Olympus, OM System, and Panasonic.